The Pathology Core will be widely used by cutaneous investigators to aid in understanding function. This Core will provide service, instruction and interpretation. Since light microscopy and specifically routine histology and immunohistochemistry were indicated to be of the greatest general use to the SDRC members, service will be in the form of tissue processing, sectioning and staining to elucidate the morphology of specific epithelia. Investigators will be able to detect expression of genes at the message and protein levels through the use of in situ hybridization and immunohistochemical techniques, respectively. Another unique feature of the Pathology Core highly requested by SDRC users is access to a library of epithelia from various laboratory species, and the Core will include a tissue repository. Service will be in the form of expertise and instruction in more highly specialized morphological services such as laser capture microdissection, novel antibody evaluation and computer-assisted image analysis. Interpretation will help investigators evaluate whether phenotypic changes seen in epithelia from their engineered mice are different from those of wild type mice. This feature of the Core draws on the expertise that the Director and co-Directors have in investigating numerous stratified squamous epithelia and their appendages. We anticipate, based on our experience that the Pathology core will provide services, training and interpretative abilities that exceed the capabilities of the individual investigators and thus will result in the strengthening and the development of new collaborative ventures in epithelial biology.